This article was co-authored by Claudia Carberry, RD. Claudia Carberry received her MS in Nutrition from the University of Tennessee Knoxville in 2010 and works as an outpatient dietitian.

There are 27 references cited in this article, which can be found at the bottom of the page.

Thanks to the low-carbohydrate diet fad, most people believe that carbohydrates are unhealthy and should be avoided, especially by people who are attempting to lose weight. The truth is that there are different types of carbohydrates, and each kind has a different effect on the body. The glycemic scale was created to create a measurement of these effects. To eat low on the glycemic index, you essentially need to focus on whole, unprocessed foods, including fruits and non-starchy vegetables.

Steps

Part 1

Understanding the Glycemic Index

1

Understand what the glycemic index is. The glycemic index is a scale that ranks foods according to how much they raise blood glucose levels. Usually, the scale is a comparison to another food, such as pure glucose.[1]

Carbohydrates are ranked according to the way that they affect an individual’s blood glucose levels. The higher a food's glycemic index, the more it affects blood sugar and insulin levels. When the carbohydrates in a food cause a person’s blood sugar to spike, it is considered a high-glycemic food. Low-glycemic foods do not have a significant effect on blood sugar, and foods that fall somewhere in the middle are considered moderate-glycemic foods.[2]

GI is actually measured by feeding the food to 10 healthy adults (who had fasted) and checking their blood sugar periodically. The GI is based on the averages.[3]

2

Know who it helps. This scale is primarily meant to help people with diseases like diabetes. Utilizing the glycemic index is very helpful for women suffering from Polycystic Ovarian Syndrome too, as these women typically have insulin resistance. This causes the woman's body to resist the effects of insulin, causing prolonged blood sugar spikes and eventually diabetes. Following a low-glycemic index diet can significantly lower blood sugar spikes in these individuals. It is also helpful for people who want to lower their carbohydrate intake or who want to lose weight.[4]

3

Eat low-glycemic foods to feel full. Because low-glycemic foods are absorbed more slowly, they help you feel fuller for longer. Therefore, they help control your appetite.[5]

4

Understand what affects the glycemic index. Many factors can affect a food's GI. For instance, processing can increase a food's GI, such as a grape, which has a lower GI, compared to grape juice, which has a higher GI.[6]

Other factors that can affect the GI are how long you cook the food (pasta that is cooked longer has a higher GI), the type (some types of rice have a higher GI than others), and how ripe a piece of fruit is.[7]

5

Know what foods the glycemic index applies to. GI numbers are only assigned to foods that have carbohydrates in them.Therefore, foods such as oil or meat do not have a GI number.[8]

6

Learn what constitutes a low-glycemic food. Generally, foods that are rated 55 or less are considered low-glycemic foods, while medium foods are in the 56 to 69 GI range. Anything above that is considered high.[9]

Part 2

Finding Foods to Eat

1

Check a glycemic index for low-glycemic foods. The easiest way to find low-glycemic foods is to check glycemic indexes. They will offer you a wide variety of low-glycemic foods.[10]

2

Focus on whole grains. Whole grains fall into the category of "complex carbohydrates," and they almost always have a lower GI than more processed varieties. Whole wheat varieties of bread and pasta, oatmeal, muesli, barley, and lentils all have low GIs.[11]

Beans are also low on the glycemic scale. For instance, black beans, navy beans, and kidney beans all come in at about 30.[12]

Claudia Carberry, RD

Registered Dietitian

Claudia Carberry received her MS in Nutrition from the University of Tennessee Knoxville in 2010 and works as an outpatient dietitian.

Claudia Carberry, RD Registered Dietitian

Combine your complex carbs with proteins. According to registered dietitian Claudia Carberry, “Whole grain carbs are the best choices when you’re on a low GI diet. Make sure you're choosing carbs that are high in fiber and eat them in combination with protein.”

3

Eat your fruits and non-starchy vegetables. Though a couple of fruits rank higher on the GI scale, eating fruits and non-starchy vegetables are usually a safe bet for low-glycemic foods.[13]

For instance, watermelon, grapes, and bananas rank relatively high at 72, 59, and 62, respectively.[14]

Grapefruit, apples, peaches, pears, and oranges all rank below 50. Grapefruit comes in at the lowest at 25.[15]

4

Stick to less-processed foods. The more processed your food is, the more likely it is to have a higher GI.[16]

Of course, this rule applies to foods like whole wheat bread versus white bread, but it also applies to foods like whole fruit versus fruit juices.[17]

Part 3

Incorporating Low-Glycemic Foods Into Your Diet

1

Pick a whole grain for breakfast. If you prefer hot or cold cereal for breakfast, pick one that incorporates or is mainly whole grains, such as oatmeal. You can also find a number of cold cereals that are composed of whole grains. Try topping it with a low-glycemic fresh fruit, such as peaches.[18]

2

Skip instant foods. These foods, such as instant rice often have a higher GI, so stick to foods you cook yourself.[19]

Instead of instant rice, cook brown rice or converted long grain rice for yourself, both of which have lower GIs.[20]

3

Pick whole grains over more processed foods. For instance, choose whole wheat bread instead of white bread. Try whole wheat pasta instead of regular pasta. These choices will help lower the GI of the foods you eat.[21] You can use these foods the same as you always do, in moderation of course.

4

Skip packaged foods as snacks. For instance, instead of eating a package of chips, try snacking on a handful of nuts. Instead of cookies, eat a piece of fruit as a snack.[22]

Hummus is also very low on the scale and loaded with protein. Eat with some low-glycemic vegetables, such as celery or bell pepper.[23]

5

Focus on fiber-rich foods. Foods with more fiber have a lower GI-index. Read labels to help you decide if foods have enough fiber. You need 25 to 30 grams per day.[24] Whole grains are typically higher in fiber, thus allowing for better blood sugar regulation. The higher the fiber content in food, the less impact it will have on blood sugar.

6

Eat protein with carbohydrates. Even when eating low-glycemic foods, you should combine those foods with low-fat proteins such as fish. This combination helps you feel fuller longer and lowers the GI for the meal.[25]

7

Eliminate foods that carry a high-glycemic load. Foods that carry a high-glycemic index rank at 70 or above on the glycemic index.

Learn about low-glycemic foods (0-55) that can replace high-glycemic foods in some of your favorite recipes, such as subbing zucchini noodles for regular noodles. By substituting the healthier glycemic option, you will find that you can still enjoy many of your favorite dishes without causing a spike in your blood sugar levels.

For moderate glycemic index foods, eliminate anything that ranks between 56 and 69 that you can do without. Keep only the foods that you must have, and consume them in moderation. Continue to enjoy your favorite foods by eating them in their healthiest form. For example, substitute a fresh peach for a cup of canned peaches.

8

Incorporate fruits and non-starchy vegetables at every meal. Fruits and vegetables are high in fiber and thus, have a minimal impact on blood sugar. Focus on fruits that have skins/seeds, such as berries. These are highest in fiber and pack the best nutritional punch. Vegetables are all highly fibrous, but cruciferous vegetables are especially beneficial. At mealtimes, make sure at least half of your meal is fruits and non-starchy vegetables. Try a fresh, green salad with vegetable toppings, such as bell pepper, cucumber, and tomato, or eat a light mix of fresh peaches, pears, and apples.[26]

Tips

Consult your doctor or nutritionist if you would like help determining your optimal daily GI load.

Although eating low-glycemic foods may be necessary to improve your health, remember that you can occasionally eat foods that are high on the glycemic index; just try to compensate at the next meal to keep down your total glycemic load for the day.

Warnings

The glycemic index is not perfect. In fact, the combinations of food you eat can change the glycemic values of food.[27] This is especially true with proteins and fats. They significantly reduce the impact of high GI foods on blood sugar. For instance, eating natural almond butter with a banana will help to balance out the impact of the high-GI banana due to the protein and fat content within the almond butter.